Single phase induction motors

1. The motor used for the compressors is

d.c. series motor
shaded pole motor
capacitor-start capacitor-run motor
reluctance motor

Detailed SolutionThe motor used for the compressors is

2. The speed control of universal motor used for sewing machines is by

friction
varying the resistance
tapping the field
centrifugal mechanism

Detailed SolutionThe speed control of universal motor used for sewing machines is by

3. The running winding of a single phase motor on testing with Meggar is found to be ground. Most probable location of the ground will be

At the end connections
At the end terminals
Anywhere on the winding inside a slot
At the slot edge where coil enters or comes out of the slot

Detailed SolutionThe running winding of a single phase motor on testing with Meggar is found to be ground. Most probable location of the ground will be

4. In split-phase motor auxiliary winding is of

thick wire placed at the bottom of the slots
thick wire placed at the top of the slots
thin wire placed at the top of the slots
thin wire placed at the bottom of the slots

Detailed SolutionIn split-phase motor auxiliary winding is of

5. In a single phase motor the centrifugal switch

disconnects auxiliary winding of the motor
disconnects main winding of the motor
reconnects the main winding the motor
reconnects the auxiliary winding of the motor

Detailed SolutionIn a single phase motor the centrifugal switch

6. A repulsion motor is equipped with

slip rings
commutator
both (A) and (B)
none of the above

Detailed SolutionA repulsion motor is equipped with

7. A schrage motor can run on

zero slip
negative slip
positive slip
all of the above

Detailed SolutionA schrage motor can run on

8. The speed of a universal motor is usually reduced by using

gearing
belts
brakes
chains

Detailed SolutionThe speed of a universal motor is usually reduced by using

9. If a D.C. series motor is operated on

spark excessively
have poor efficiency
series motor is operated on A.C. supply, it will A. spark excessively B. have poor efficiency C. have poor power factor
all of the above

Detailed SolutionIf a D.C. series motor is operated on

10. Single phase induction motor usually operates on

0.6 power factor lagging
0.8 power factor lagging
0.8 power factor leading
unity power factor

Detailed SolutionSingle phase induction motor usually operates on

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